The big picture: Fungi are essential for ecosystem function


  • 100,000 species described
    • estimated 1.5 million species
    • diverse size, morphology and habitats


  • Heterotrophic: eat via absorption
    • parasites, decomposers, mutualists
    • recycle nutrients via decomposition


  • Cell walls made of chitin
    • ‘mushrooms’ are only a part of the body
    • filaments belowground for absorption


  • Wild reproduction

Chitin and Heterotrophs → Animals & Fungi


Fossil Fungi




  • Oldest fungal fossils appear ~900 mya
    • split from aquatic eukaryotic ancestor 1 bya(?)


  • Fossils of fungal spores found in Wisconsin dated to 460 mya
    • suggests origin of land-based fungi


  • Fungi and plants moved onto land around same time
    • what was the benefit for fungi?
    • helped vascular plants invade the land!
    • mycorrhizal symbiosis @ 405mya during Devonian period

All fungi share traits related to nutrition

Fungal derived enzymes and humans: Cellulase


Fungal derived enzymes and humans: Statins


Fungal body plan: Not-motile and mostly multi-cellular


Most hyphae divided into cells by septa


Specialized hyphae also exist




  • Specialized hyphae for feeding on live animals
    • hoops that can snare prey


  • Specialized hyphae that allow extraction of nutrients from plants
    • mycorrhizal fungi


  • Mutualistic fungi have branching hyphae they use to exchange nutrients with plant hosts
    • Arbuscules invade roots cell walls
    • Other hyphae can create a ‘sheath’ around root cells

Mycelium: huge surface and volume for absorption


Mycorrhizal fungi: sharing with plants




  • ~80-90% of plants have association with fungus
    • fungi exist in/around plant roots
    • share what resources?
    • how much sharing is not known


  • 2 main types:
    • Ecto and Arbsucular mycorrhizae


  • Association now key for plants to thrive
    • fungi more efficient @ nutrient uptake

Fungi rule the world: plants evolution linked to symbiosis


Fungal life cycles (Haplonic)



  • Life cycles can be complex
    • spores are produced sexually or asexually
    • spores and nuclei of hypae are haploid (1N)


  • Lots of spores are produced


Sexual Reproduction:

1. Plasmogamy:

2. Karyogamy:

Fungal life cycle: basic


Fungal lineages (no longer clean groups)


Fungal lineages (no longer clean groups)


Fungal-animal mutualisms


Fungal-animal parasitism: Is ‘The Last of Us’ Real?!?